METHOD FOR PRODUCING A MULTI-LAYER LACQUER FINISH

摘要

The present invention relates to a method for producing a multi-layer lacquer finish on a metal substrate, wherein a base lacquer coat or a plurality of directly consecutive base lacquer coats are produced directly on a metallic substrate coated with a hardened electrophoretic dip coat, a clear lacquer coat is produced directly on the one or the upper of the plurality of said base lacquer coats, and the one or the plurality of base lacquer coats and the clear lacquer coat are subsequently hardened together. The method is characterized in that at least one base lacquer employed for producing the base lacquer coats comprises at least one aqueous dispersion which contains at least one copolymer (MP). The copolymer (MP) can be produced by providing an aqueous dispersion of at least one polyurethane followed by polymerization of a mixture of olefinically unsaturated monomers in the presence of the polymer produced in (i), a water-soluble initiator being employed, and the dosing of the olefinically unsaturated monomer being performed such that in the reaction solution a concentration of 6.0 wt.% relative to the total amount of the olefinically unsaturated monomers employed for polymerization is not exceeded during the entire reaction time and the mixture of olefinically unsaturated monomers containing at least one olefinically polyunsaturated monomer and at least one linear hydroxy-functional reaction product (R) having an acid number of less than 20 mg KOH/g. During the production of said reaction product at least one compound (v) is employed which comprises two functional groups (v.1) and, arranged between the functional groups, an aliphatic or araliphatic hydrocarbon group (v.2) having 12 to 70 hydrocarbon atoms.